Guangzhou has been ridiculously full over the last year. My company sends about 10-12 people to China every month and while we prefer to use Guangzhou as our gateway since a lot of our work is in Guangdong, Shaanxi and Hainan, we simply cannot find seats to there anymore. I just had to send 9 people to Sanya via Beijing last week, because the Guangzhou flights simply didn't have enough seats the entire week. In my personal experience as well (5 flights last year), every single flight is absolutely packed (mainly African and middle Eastern traders) and there are sometimes 200+ Golds on the flight.